I had sheets of glow-in-the-dark vinyl for use as a table decoration at events and had been meaning to cut it into strips to turn into a display of sorts. I found a nice printer on the sidewalk perfect for rescuing parts from. 3D printer, maybe?. Or the paper feed mechanism would be perfect to feed some glow vinyl constantly. So I set down to build a simple addressable UV LED strip as a "print head". Just using 12 8b latching shift registers, 96 2012mm UV LEDs and the same amount of limiting resistors, drive transistors.

The UV print head took about a week of lazily soldering it together and assuming my blind shift register wiring worked based on the datasheet - it did, first try! Cuting the vinyl into strips, coating the backside with flour to remove they stickyness, and removing the too-small guides from the printer feed mechanism took just a couple hours. I made new "guides" with bits of wire tied at the edges. The motor from this particular printer is a simple DC drive, not a stepper as expected! As an after-thought I added a MOSFET to allow me control over when the feed motor turns on and off in code, to pause after messages. Under testing, it drew less than 1 Amp at 5VDC!